One-way clutches are commonly employed in automatic transmissions for automobiles. A one-way clutch allows a first clutch plate to free-wheel in a first rotational direction relative to a second clutch plate, and to clutch in a second rotational direction. Examples include roller clutches and sprag clutches.
It may be desirable to have the one-way clutching mode operable only upon demand, such that it is in free-wheeling mode in both directions until the one-way clutching is selectively actuated. There are different means of selecting when the free-wheeling stops and one-way clutching begins.
There exists a need for a simple selectable one-way clutch which allows free-wheeling in both directions when the clutch is not actuated. When the clutch is actuated, the clutch plate may be held fixed from rotating in a first direction, but allowed to rotate in a second, overrun direction.